1. Field of the invention
This invention relates to a sorter, a sheet jogging device and a stapling device, in particular a compact type sorter, which can shift trays sequentially and vertically up and down with minimal power by using a disk cam type wheel having a groove crossing the disk surface in a curved line, an improved sheet jogging device which does not overload a drive means and a stapling device which is operated without a separate drive means therefor.
2. Information Disclosure Statement
There is an increasing need for a compact, speedy and low-noise sorter for a copying machine (automatic sheet sorting device) and a multi-function sorter which can further execute such various functions as jogging and stapling the collated sheets in the sorter.
The above needs may be divided into two functional categories. One is an effective automatic sorting mechanism of copy sheets, and the other is a post-sorting method of handling the sorted sheets, that is jogging and stapling.
Sheet sorting is necessary to produce multiple sets of copies of multiple page documents. It requires transfer means and plural trays to sort and accommodate the copy sheets into collated sets. In order to meet this functional requirement and further requirements of simplicity of operation and compact size, various sorting machines have been devised in which a plurality of trays are stacked in a compact or closely spaced relation reducing the space occupied by the trays while sorting the copy sheets between adjacent trays.
Among those sorters a shiftable tray or bin type (the "Tray Shifting Type") sorter is especially noteworthy. It discharges copy sheets successively to trays shifted vertically up and down and spaced widely enough in the outlet for easy entry of the copy sheets between adjacent trays. Every Tray Shifting Type sorter essentially includes two functions. One function is shifting the trays vertically from a first closely spaced relation at one side of the sheet outlet to a second closely spaced relation at the other side of the sheet outlet while the other function is widening the gap between adjacent trays at the outlet to accommodate sheet entry.
The two typical models of Tray Shifting Type are a sorter using a cylindrical cam having a helical groove on its circumferential lateral surface and a sorter using a notched disk cam having one or two slots radially and functioning as a Geneva movement.
U.S. Pat. No. 4,337,936 (Jul. 6, 1982) and U.S. Pat. No. 4,343,463 (Aug. 10, 1982) granted to Mr. Frederick J. Lawrence, disclosed a Tray shifting Type sorter using a pair of cylindrical cams. In Lawrence's sorter, a couple of cylindrical cams having a helical groove on their circumferential surfaces are installed in opposite sides at the sheet outlet and trays are stacked at the upper side of the cylinder cams in their first closely spaced relation. The tray has a pair of trunnions on the opposite lateral sides, which engage the cylindrical cams. The trays are moved downward while the trunnions pass the helical grooves of the cylindrical cams successively when the cylindrical cam is revolving. The tray passing the cylindrical cam is pivotally and widely spaced apart from the upper stacked trays and a copy sheet is discharged on the tray by a transfer roller of a copying machine during the pivotal movement of the tray. The trays are stacked at the lower side in their second closely spaced relation after accommodating the copy sheets successively.
Another U.S. Pat. No. 4,466,609 (Aug. 21, 1984) granted to Mr. Lawrence, disclosed a cylindrical cam type sorter which shifts trays up and down by installing a couple of spaced apart cylindrical cams on each side of the outlet in order to shift the trays in parallel rather than in a pivotal manner.
In all the Lawrence's sorters using cylindrical cams, the cylindrical cams are generally rotated by the revolution of cam shafts fixed in the cylindrical cams, which are supported by locational bearings and driven through belts by a motor located at the upper center of the sorter. The movement of the trays according to the mechanism is smooth and continuous since the trunnion flows through the rotating helical groove as if it is rolling down a slope continuously and linearly. However the cylindrical cams and the upper installed motor require relatively large spaces in the side and upper parts of the sorter, and therefore they limit compactness of the sorter.
U.S. Pat. No. 4,328,963 (May 11, 1982), U.S. Pat. No. 4,332,377 (Jun. 1, 1982), U.S. Pat. No. 4,397,461 (Aug. 9, 1983), and U.S. Pat. No. 4,466,608 (Aug. 21, 1984) granted to R. Clark DuBois and John C. Hamma disclosed another Tray Shifting Type sorter using disk type cams. Their basic approach provides a disk type cam having one or two notched slots radially on each side of the outlet. The disk cam receives a trunnion of a tray in the slot and rotates to widen the tray spacing at the outlet during their Geneva movement.
This sorting mechanism greatly simplified the drive device as a center shaft connected both disk cams together in their centers and it greatly reduced the installation space required for the cams and motor by installing the shaft and the motor inside the sorter and by attaching the relatively thin disks on the side walls of the sorter. Therefore the sorter of DuBois et al is permitted a relatively simple and compact sorter. In the sorting mechanism of DuBois et al, a pair of trunnions of a tray are compressed by spring or dropped by weight into the slots of the disk cam for widening the spacing of the adjacent tray at the outlet and shifting the trays from a first closely spaced relation at one side of the disk cam to a second closely spaced relation at the other side of the disk cam. According to the above mechanism, the trays are shifted upwardly or downwardly with the trunnions being received in the slots of the disk cams, the tray is pivotally widened by rotation of the disk cam at the outlet and a copy sheet enters through such widened gap on the tray, and then the disk cam discharges the trunnion in order to stack the trays at the other side of the outlet.
However, the DuBois and Hamma sorter is noisy because of the impact between the trunnion and the slot of the disk cam, when slots of the disk cams approach, accommodate, and discharge trunnions. Furthermore, the driving operation is not continuous and smooth because the disk cams endure different loads in a rotation according to whether they accommodate the trunnions therein. Moreover, the motion to accommodate the trunnion into the slot of the disk cam requires additional time, so that the DuBois and Hamma sorter can not be adapted to a high-speed copying machine.
In every Tray Shifting Type sorter, the spacing between trays is a major factor which decides the number of copy sheets that can be accommodated in a tray; and the spacing is defined by the diameter of a trunnion. Further, recently developed sorters have adopted guide pins together with the trunnions, which are formed on front edges of a tray and are captured in guide holes of a couple of separate guide members for trays. Guide members are attached opposite each lateral surface of the assembled trays and have a plurality of guide holes which support and guide the guide pins in order to keep the front ends of the trays spaced apart as wide as the rear ends of the trays.
In the prior trays, a guide pin has a diameter smaller than that of a trunnion and a guide hole has width slightly larger than the diameter of the guide pin. On assembling the trays and the guide member in a sorter, generally the trays are mounted in a sorter body and then a pair of guide members are attached to the subassembled trays. However, the operation for assembling the guide member to the trays, is laborsome since the spacing of the guide holes is different from that of stacked guide pins. Further, the guide member may fall out of the guide pins as a result of accident or vibrations during sorting operation since the guide pins are loosely fitted into the guide holes.
Accompanying the development of sorting mechanisms, multi-function sorters have been developed to align and staple the sorted sheets. Multi page documents are generally stapled after copying the documents, and therefore it is desirable to staple the copy sheets on a sorter.
The conventional jogging device, which assembles the collated sorted copy sheets into aligned sets prior to stapling, uses a pivot arm which is activated by a driving gear and a driven gear, as suggested in U.S. Pat. No. 5,090,673. However, the device has shortcomings in that the drive means often is overloaded and noisy during operation.
The structure and problems of a sheet jogging device according to the prior art are as follows:
FIG. 16A is a perspective view of a sheet jogging device according to the prior art and FIG. 16B is a plan view of FIG. 16A showing a tray only among a number of trays for illustrative convenience.
A number of trays 201 installed at an outlet part 200 of a copying machine are moved upward and downward along front and rear posts 205F and 205R connecting an upper frame 203 and a lower frame 204 of a tray housing 200. The front flanks of the tray 201 contact and slide along the front posts 205F, respectively, as the rear flanks of the tray 201 are coordinated with the rear posts 205R (for illustrative convenience, only one front post and one rear post are shown as a whole and the other ones are partially cut off in FIG. 16A). A slot 205S is formed vertically in each rear post 205R, and a tray 201 has a pair of rollers 201R opposite each rear flank. Therefore, as the rollers 201R move upward and downward along the slots 205S, the tray 201 can slide vertically along the rear posts 205R. The tray 201 has an arc-shaped guide hole 201H therein.
A drive means 206 and a driving gear 207 mounted on the top of the drive means 206 are located at the lower frame 204 and a driven gear 208 is geared with the driving gear 207. A shaft for the driven gear 208 and a rotational shaft 209 are formed as integral parts and coaxially mounted between the upper frame 203 and the lower frame 204, and an upper arm 211 and a lower arm 212 are fixed to the upper end and to the lower end of the shaft 209, respectively. An alignment rod 210 in parallel with the rotational shaft 209 is fixed to the front ends of the upper arm 211 and the lower arm 212 therebetween. The alignment rod 210 is installed into the guide holes 210H of the trays 201. Item 290 in FIG. 2 illustrates a stapler unit.
When copy sheets are distributed on the tray 201 ("X" position in FIG. 16B) from the outlet of a copying machine the driving gear 207 and the driven gear 208 are rotated by the drive means 206 to align the copy sheets. In accordance with a rotation of the driven gear 208, the rotational shaft 209 revolves and therefore the upper arm 211 and the lower arm 212 fixed to the rotational shaft 209 move curvilinearly pivoting on the shaft 209 in the guide hole 210H of the tray 201. The action moves and aligns the copy sheets to "Y" position of FIG. 16B at the same time. Then the aligned copy sheets are generally stapled by a stapler unit 290.
However, the following problems occur during the operation of the sheet jogging device as described above.
First, when the alignment rod contacts the copy sheets for alignment, the contact force imposes loads to the drive means, which sometimes causes breakdown of the drive means as well as consuming excess amount of energy.
Second, the loads acting to the drive means are not uniform in accordance with the sizes of the copy sheets such as A4, B5 since the alignment bar contacts the copy sheets in different locations.
Third, as the driving mechanism for the sheet jogging device adopts the engaged gears, they cause a lot of noises during the operation.
On the other hand, as a stapler used for the prior stapling device in a sorter generally needs a separate drive means therefor, it is regarded as an obstacle to providing a compact and economic stapling sorter.
It is the primary object of this invention to provide a compact sorter using a disk type cam which can be operated continuously and with uniform load.
Another object of the invention is to provide a disk cam type sorter which can be operated smoothly and silently in high-speed sorting.
A further object of this invention is to provide an economical sorter capable of operating with low power consumption.
Another object of this invention is to provide improvements in a tray and a guide member which can be easily and securely matable each other and also provide an assembly type tray in which guide pins and/or trunnions are comprised of separate members to be mated with a tray member.
An additional object of this invention is to provide a sheet jogging device in which a drive means can be protected from overload by using a tension change means and which can decrease noise by using a wire as power transmission means for jogging member.
Another object of this invention is to provide a stapling device in which a stapler assembly can be easily attached and detached in a sorter and which is driven by the drive motor for discharging the sheets at outlet without an separate motor.
Finally, this invention aims to provide a more compact and effective stapling sorter.